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Message ID: 3617     Entry time: Tue Sep 28 21:11:52 2010
Author: koji, tara 
Type: Update 
Category: Electronics 
Subject: Fixing the new TTFSS 

We found a small PCB defect which is an excess copper shorting circuit on the daughter board,

it was removed and the signal on mixer monitor path is working properly.


 We were checking the new TTFSS upto test 10a on the instruction, E1000405 -V1. There was no signal at MIXER mon channel.

It turned out that U3 OpAmp on the daughter board, D040424, was not working because the circuit path for leg 15 was shorted

because of the board's defect. We can see from fig1 that the contact for the OpAmp's leg (2nd from left) touches ground.

We used a knife to scrap it out, see fig 2, and now this part is working properly.


Attachment 1: before.jpg  145 kB  Uploaded Tue Sep 28 22:13:49 2010  | Hide | Hide all
Attachment 2: after.jpg  330 kB  Uploaded Tue Sep 28 22:14:15 2010  | Hide | Hide all
Attachment 3: before.jpg  55 kB  Uploaded Wed Sep 29 02:50:54 2010  | Hide | Hide all
Attachment 4: after.jpg  108 kB  Uploaded Wed Sep 29 02:51:14 2010  | Hide | Hide all
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